Oates Joanne, Faust Belinda, Attrill Helen, Harding Peter, Orwick Marcella, Watts Anthony
Department of Biochemistry, University of Oxford, Oxford, UK.
Biochim Biophys Acta. 2012 Sep;1818(9):2228-33. doi: 10.1016/j.bbamem.2012.04.010. Epub 2012 Apr 20.
Understanding the role of specific bilayer components in controlling the function of G-protein coupled receptors (GPCRs) will be a key factor in the development of novel pharmaceuticals. Cholesterol-dependence in particular has become an area of keen interest with respect to GPCR function; not least since the 2.6Å crystal structure of the β2 adrenergic receptor revealed a putative cholesterol binding motif conserved throughout class-A GPCRs. Furthermore, experimental evidence for cholesterol-dependent GPCR function has been demonstrated in a limited number of cases. This modulation of receptor function has been attributed to both direct interactions between cholesterol and receptor, and indirect effects caused by the influence of cholesterol on bilayer order and lateral pressure. Despite the widespread occurrence of cholesterol binding motifs, available experimental data on the functional involvement of cholesterol on GPCRs are currently limited to a small number of receptors. Here we investigate the role of cholesterol in the function of the neurotensin receptor 1 (NTS1) a class-A GPCR. Specifically we show how cholesterol, and the analogue cholesteryl hemisuccinate, influence activity, stability, and oligomerisation of both purified and reconstituted NTS1. The results caution against using such motifs as indicators of cholesterol-dependent GPCR activity.
了解特定双层膜成分在控制G蛋白偶联受体（GPCRs）功能中的作用将是新型药物研发的关键因素。尤其是胆固醇依赖性已成为GPCR功能方面备受关注的领域；这一点尤其重要，因为β2肾上腺素能受体的2.6Å晶体结构揭示了一个在A类GPCR中保守的假定胆固醇结合基序。此外，在少数情况下已证明了胆固醇依赖性GPCR功能的实验证据。受体功能的这种调节既归因于胆固醇与受体之间的直接相互作用，也归因于胆固醇对双层膜有序性和侧向压力的影响所导致的间接效应。尽管胆固醇结合基序广泛存在，但目前关于胆固醇在GPCRs功能中作用的现有实验数据仅限于少数几种受体。在这里，我们研究胆固醇在A类GPCR神经降压素受体1（NTS1）功能中的作用。具体而言，我们展示了胆固醇及其类似物胆固醇半琥珀酸酯如何影响纯化和重组NTS1的活性、稳定性和寡聚化。结果提醒人们不要将此类基序用作胆固醇依赖性GPCR活性的指标。
